Waterproof roofing and paving composition.



psi-Tun STATES ra'rsnr OFFICE;

PATRICK J. MCNAIIIARA,- or VANCOUVER, rearrxsn ooLUMBrA, CANADA.

WATERPROOF ROOFING. AND PAVII IG CQ MfOSITION'.

He Drawing.

To all whom it may concern.

Be it known that I, PATRICK J. MoNA- NARA, a citizen of the Dominion of Canada, residing at Vancouver, in the Province of British Columbia, Canada, have invented certain new and useful Improvements in Waterproof Roofing and Paving Compositions, of which the following is a specification. g

This invention relates to a water-proof roofing and paving composition which "is designed as a cheap and fully advantageous substitute for the asphalt or asphaltic compositions at present used for such purposes.

The proportions of the several ingredients and the manner of mixing the same are'fully described in the following specification and are summarized in the appended claims.

The composition consists of the following ingredients mixed in the proportions given in accordance with the directions thereafter.

Four parts by bulk of" pitch whichis thinned slightly by the addition to it of a small amount of the crude material from which the pitch is derived.

Three parts by bulk. of

One part of common salt. I

The pitch is first melted and while in the molten state suflicient of the material from which the pitch is derived to thin the pitch as may be found desirable and the thinning agent is thoroughly mixed withthe pitch. If coal tar pitch is used it will be thinned with coal tar, raw or refined, and if crude slalred lime, and

' oil pitch is usedit will be thinned with crude oil.

While the pitch is hot an equivalent vol ume of the slaked lime and salt thoroughly mixed together, is stirred in and the whole is boiled for about two hougs with frequent stirring. The thinning of the pitch with the small proportion of the material from which it was derived and the boiling of the lime with that slightly reduced pitch enables .it to thoroughly permeate the particles of lime and the lime and pitch are incorporated as a thoroughly homogeneous composition.

The composition is applied while hot as :equired. If applied to paper or burlap for roofing or walls the proportion of the diluent to the pitch should be'such that when cold the composition will not splinter or break from it when the material to which it is appiied is bent, but a less proportion of the diluent is required when the composi- Specification otletters Patent.

tion is to be spread as a layer ineither roofing or paving, and a slightly greater proportion of lime ma .be' used.

The composition ma e in the approximate proportions given and mixed and boiled in the manner described, will, when cold, form a hard and durable surface that is not materially affected by ordinary atmospheric changes of temperature.

' I amaware that pitch and tar mixed with sand, cement or clay have been commonly used in various roofing and paving compositions, but the constituents of the pitch and tar do not permeate such ingredients, and as a consequence. the composition is liable to disintegrate and crumble: while, when mixed and-boiled with lime, the particles of limeseem to be thoroughly permeated with the tar and incorporated with the pitch, so that it forms a thoroughly homogeneous composition, and it is my opinion that in the boiling of the pitch, lime and salt together some chemical change occurs which renders the composition particularly hard and tough, and while it does not soften with moderate changes of temperature it forms a plastic mass at a much lower temperature than when mixed with silicious materialsuch as sand or cement, which renders it more economical to apply, and favorable for application to roofs.

The composition prepared in accordance with this specification may, if considered desirable, be further mixed with clean sand or gravel but this association forms no part of the claims of this application.

Having now particularly described my invention, I hereby declare that what I claim as new and desire to be protected in by Letters Patent, is:

1-. A roofing composition which comprises the product obtained by intimately associating pitch thinned out with tar while hot with a mixture of slaked lime and common salt, substantially as specified.

' 2. A composition of the character stated which comprises the following ingredients only: coal tar, lime, salt and pitch.

In testimony whereof I afhx my signature in presence of two Witnesses.

PATRICK J. MoNAMARA.

Witnesses ROWLAND BRrr'rAIN, MAY "Wnrrn.

Patented July 31, 1917. Application filed November my 1914. Serial No. 871,806. I 

